TAIPEI (Taiwan News) — The virus in Taiwan’s African swine fever case is genetically close to strains from China and Vietnam, though its exact origin remains undetermined.

The Ministry of Agriculture confirmed the case on Oct. 25. Analysis shows 99.95% similarity to a Chinese strain and 99.92% similarity to a Vietnamese strain, according to CNA and PNN.

The ministry will submit the gene sequencing data to the World Organization for Animal Health to aid global monitoring. Du Li-hwa (杜麗華), Director General of the Animal and Plant Health Inspection Agency, said sharing the data is voluntary but provides valuable insight into circulating strains.

Deng Ming-chung (鄧明中), director general of the Veterinary Research Institute, explained that gene sequencing reveals only the arrangement of the virus’ genes, which can evolve. The virus in Taiwan's case is over 99.95% similar to a recombinant strain from China, differing at just five positions out of 10,000.

Determining its exact origin depends on whether these differences match sequences in existing databases. Without a match, authorities can only estimate its likely source.

Enhanced biosecurity measures remain in effect. Inspections of more than 5,200 farms have returned negative results, and second-round testing of 22 farms found no new infections.

However, the Central Emergency Operation Center reported Friday that samples from three areas of the Taichung pig farm where the first ASF case was detected tested positive. A total of 115 military personnel assisted with cleaning, and the veterinary institute will conduct resampling after disinfection.

Authorities said there are no signs ASF has spread beyond Taichung. Taiwan aims to return to zero cases and, after three months without new infections, regain ASF-free status.